Time to consolidate odd-even gains through right strategy, say experts

New Delhi: The city government's odd-even formula to curb rising air pollution came to an end today with Chief Minister Arvind Kejriwal describing it "highly successful". Put in place from 1 January this year, the emergency step, environmentalists believe, resulted in Delhi's lowest pollution peak compared to the previous high-smog episodes this winter.

Keeping the pollution down? AFP

But now that the experiment is over, what? Is there a concrete plan to consolidate the gains over the last fortnight and take it forward? Experts say short and medium term strategies are required on an urgent basis as a critical step ahead.

"A very big impact of the odd-even test has been that a strategy has been chalked out to reduce traffic volume on the road. It has helped public transport to become more efficient. The buses, autos and taxis could do more kilometres, more trips and carry more people. In some way, the odd-even actually forced people to decongest roads for its equitable use by them. Now, we need more permanent strategies to achieve a similar kind of situation to be able to sustain the gains. The gains are in terms of reduced congestion, which also reduced pollution because vehicles caught in traffic emit double the pollutants," Anumita Roy Chowdhury, executive director - research and advocacy, told Firstpost.

In addition, she said, the initiative made people reduce fuel cost, have actual usage of fuel and reduce their journey time. "If these are the gains we are looking for, then you need a strategy to make it happen. And this has to be sustained for a year," she said.

Asked about no significant change being observed in the level of pollution in the past 15 days, the environmentalist said, "Emergency action is taken when problems reach an emergency level. So during that time when you take such kind of action as first step, what you could do was reduce or slow down the peaking of the pollution. During the first week of January when the weather was very bad in terms of low temperature, no wind, western disturbances, pollution levels would have been higher. But that peak was actually lower than the peaks that we saw during November and December last year. This validates the importance of this emergency action."

"Of course, if you had more stringent policy with no exemptions. It would have given you greater impact. But even with the test we undertook, we observed some arresting of the peaking of pollution. So it is established that an emergency action gives you result. Now, take a lesson and design a better strategy with stringent implementation," she said.

This winter, according to the AAP government, has witnessed extremely high level of pollution. According to a CSE report, typical winter conditions — cold temperature, lower mixing height of air, calm and no-wind conditions — trap air and increase pollution. This is why winter months require emergency measures.

The months of November and December last year show higher number of days in "severe category" — four times that of the safety standard — which is the worst category according to the National Air Quality Index (NAQI).

November 2015 had 73 percent of days in severe category, said the report, against 53 percent in November 2014. December 2015 had 67 percent of days in severe category as against 65 percent in December 2014, which had at least 3 percent of days in good and satisfactory. But December 2015 had none.

During odd-even days, claimed the government, daytime has shown faster drop in pollution which was notably higher before the implementation of the scheme. Both particulate and nitrogen oxide load from cars have reduced substantially during the odd-even programme by as much as 40 percent, claimed advocate Salve, referring to the CSE study.

Pollution data by the various monitoring agencies show that air quality became much better in the second week of January compared to the first week of 2016. Real-time monitoring data of the System of Air Quality and Weather Forecasting and Research (SAFAR) reveal that pollution levels took a dip as the ambitious scheme moved to its second week.

The government is mulling implementing the scheme in a second phase as well after analysing the impact of the first phase. The details of the second phase of the private car rationing experiment will be discussed in a review meeting slated to be held by Chief Minister Arvind Kejriwal on 18 January.

Asked should this move be made permanent or what's the way ahead to control pollution in the city, Gufran Beig, scientist and project director at SAFAR, suggests that the government bolster public transport, promote non-motorised public transport for shorter distances, crackdown on builders and contractors who do not adhere to construction norms and allow construction dust to fly around.

Though he said the readings of PM2.5 - the tiniest and deadliest particulate matter which affects lungs and enters the blood stream - and PM10 - slightly larger suspended particulate matter - rose to "severe" category from "poor" - from 1 January, he refuses to accept that the odd-even formula did not work.

"Seasonal changes affect the air quality and this is one of the major reasons behind the air quality not improving despite the restriction being in place. Humidity also had been higher as compared to December. This also led to an increase in the concentration of pollutants," he concluded.